I am an American born USA Cdn dual citizen. After living and working in Canada for 42 years I retired and moved to the USA in early 2015. I enrolled in Medicare as soon as possible after I moved to the USA. Since I had only 13 SS work credits, I had to pay Medicare premiums, namely $407.00 for part A and $104.90 for part B. The part A premium has since increased slightly but the part B premium was increased to $243.60 beginning December 2015, apparently because my Adjusted Gross Income reported on my 2014 US tax return was high. Also, for reasons that I do not understand, Medicare claims that I owe an additional $2207.50 for 2015 and 2016 premiums.
Has Medicare made an error? Note that I was a Canadian resident for all of 2014, and thus although I did indeed report a high adjusted gross income on my 2014 US tax return, my US income tax liability was 0 owing to the foreign tax credit. I had almost no US sourced income in 2014.
Has Medicare made a mistake calculating my premiums?